1. Field of the Invention
The present invention relates to a coaxial cable connector plug. More specifically, the present invention relates to a coaxial cable connector plug for connection of a coaxial cable to a connector receptacle.
2. Description of the Prior Art
FIG. 1 shows a side view of a conventional coaxial cable connector plug and FIG. 2 is a sectional view of the FIG. 1 connector plug showing the internal structure thereof. The coaxial cable connector plug shown is often referred to as a push-on type. For example, as shown in FIG. 2 in a supplemental manner, the connector plug shown can be connected to a connector receptacle 1 by simply inserting the connector plug shown into the connector receptacle 1.
The push-on type connector plug comprises an inner casing 11 made of an insulating material such as insulating resin which comprises two portions, i.e. a first portion 13 and a second portion 12. The second portion 12 is fabricated by inserting a plug pin 14 of a conductive material in molding the second portion 12 such that the plug pin 14 protrudes outward. A clip 15 made of a conductive material is fixed to the root portion of the plug pin 14, such that the clip 15 extends in the direction opposite to that of the plug pin 14 and is positioned within the first portion 13. The first portion 13 is formed with a passage or an aperture 18 for receiving a center conductor 17 of a coaxial cable 16.
A shield casing 19 made of a conductive material is disposed to enclose the above described inner casing 11. An end portion of the inner casing 11 for receiving the outer conductor of the coaxial cable 16 is tapered and accordingly the shield casing 19 is also tapered at the corresponding portion. The shield casing 19 is opened at both ends in the axial direction. One end opening of the shield casing 19 faces the aperture 18 of the first portion 13 of the above described inner casing 11 and receives the inner insulation of the coaxial cable 16. The other end opening of the shield casing 19 surrounds the periphery of the plug pin 14 and a portion 19a of the shield casing 19 is adapted to be elastically inserted into a connecting portion 1b of the connector receptacle 1. The shield casing 19 is shaped such that it is favorably fixed when inserted into a cover ring 20, made of an insulating material, together with the inner casing 11.
An outer conductor 21 of the coaxial cable 16 is disposed to cover the tapered portion of the shield casing 19 and is sandwiched between a cap 22 made of an insulating material screwed on the cover ring 20 and the inner casing 11, whereby the outer conductor 21 is electrically connected to the shield casing 19 while the coaxial cable 16 is mechanically connected to the connector plug. In such a situation the center conductor 17 is sandwiched by fingers of the clip 15 and thus electrically connected to the clip 15.
Thus the push-on type connector plug is electrically and mechanically connected to the coaxial cable 16 and, by inserting the same into the connector receptacle 1, an electrical connection of the connector plug and thus the coaxial cable to the connector receptacle 1 is achieved. More specifically, the plug pin 14 of the connector plug is inserted into the receptacle aperture 1a of the connector receptacle 1 to achieve an electrical connection, while a metallic portion 1b of the connector receptacle 1 is inserted into a portion 19a of the shield casing 19 to achieve an electrical connection. Accordingly, the receptacle aperture 1a of the connector receptacle 1 is connected to the center conductor 17 of the coaxial cable 16 and the metallic portion 1b of the connector receptacle 1 is connected to the outer conductor 21 of the coaxial cable 16.
However, according to the above described structure of the connector plug, the plug pin 14 being inserted into the second portion 12 of the inner casing 11 is fabricated by cutting work. For this reason the cost of the connector plug is relatively high. Furthermore the clip 15 is fixed to the plug pin 14 by caulking and a caulking step is required in fabrication and the number of components is increased. In addition, the step of fixing the clip 15 to the plug pin 14 by caulking requires a delicate processing work, which is relatively tiresome and nevertheless could be of less reliability.